Often when a PvP battle starts the game crashes for me.
Sometimes I get a hud and no background, then it closes, other times I am at the loading screen showing a castle in the background and a loading bar that never finishes.

edit:
Three times now in a row I've had the enemy is at the gates, I clicked yes to PVP and it never begins.

The last line in my log files is always: LOGONLY: Nhoblio Refugees: State 4